(a) Field on Invention
This invention relates to the performance of a IEEE-1394 serial bus, and more particularly, but not by way of limitation, to a method of delaying or blocking new bus resets from propagating while a previous bus initialization (bus reset, tree-id or self-id) is in process. The method provides for more robust Beta only bus operation during high frequency bus resets. The bus resets are caused by noise events, power-up and power-down sequences and other bus reset causing events.
(b) Discussion of Prior Art
IEEE-1394-2008 defines Legacy or Alpha nodes and Beta nodes. Legacy nodes are based on earlier versions of the IEEE-1394 standard (IEEE-1394-1995 and IEEE-1394a-2000), while Beta nodes are based on IEEE-1394b-2002. There are many differences between Legacy node and Beta node implementations. But, for the purposes of this application, Legacy nodes do not support loops in a topology while Beta nodes do support loops in the topology. By definition, a loop in a topology is where a node port connects back to the same node through 0 to N nodes in a node cloud.
Heretofore, there have been a number of IEEE 1394-coupled communication system and method patents. For example, they are U.S. Pat. No. 7,681,051 to Liu et al., U.S. Pat. No. 7,036,031 to Takeuchi, U.S. Pat. No. 6,912,596 to Skidmore, U.S. Pat. No. 6,523,073 to Kammer et al., and U.S. Pat. No. 6,412,076 to Honda et al.
None of these patents describe the unique features and method for specific improved robustness of Beta only bus topologies by delaying or blocking new bus resets from propagating during bus initialization.